1347. Minimum Number of Steps to Make Two Strings Anagram

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題目敘述

You are given two strings of the same length s and t. In one step you can choose any character of t and replace it with another character.

Return the minimum number of steps to make t an anagram of s.

An Anagram of a string is a string that contains the same characters with a different (or the same) ordering.

Example 1

Input: s = “bab”, t = “aba” Output: 1 Explanation: Replace the first ‘a’ in t with b, t = “bba” which is anagram of s.

Example 2

Input: s = “leetcode”, t = “practice” Output: 5 Explanation: Replace ‘p’, ‘r’, ‘a’, ‘i’ and ‘c’ from t with proper characters to make t anagram of s.

Example 3

Input: s = “anagram”, t = “mangaar” Output: 0 Explanation: “anagram” and “mangaar” are anagrams.

解題思路

Solution

public class Solution {
    public int minSteps(String s, String t) {
        int[] countS = new int[26];
        int[] countT = new int[26];

        for (char ch : s.toCharArray()) {
            countS[ch - 'a']++;
        }

        for (char ch : t.toCharArray()) {
            countT[ch - 'a']++;
        }

        int steps = 0;
        for (int i = 0; i < 26; i++) {
            steps += Math.abs(countS[i] - countT[i]);
        }

        return steps / 2;  
    }
}